From BP's claim to be moving "beyond petroleum" to Exxon Mobil's "promise of technology," the companies that fill our gas tanks are trying their darnedest to build an eco-friendly image. But will the pitch pay off with investors? Only if the effort is sincere, say two major firms [Sustainable Asset Management, Innovest] that specialize in evaluating companies' stock market prospects based on their social-responsibility credentials. [refers to BP, Shell, ExxonMobil, KPMG]